The present invention relates to molten metal samplers. More specifically, the invention relates to devices having cavities for obtaining samples of a molten metal for the purpose of determining the composition or characteristics of the molten metal by spectrographic analysis, and wherein provision is made for adding a material for promoting carbide formation in the molten metal as it cools.
To spectrographically analyze a molten metal to determine its composition, it is common practice to obtain small sample castings or samples for analysis. In order to make an accurate analysis of molten iron, it is desirable to obtain samples of uniform composition, density and structure such as white iron, in which the carbon remains dissolved or interspersed in the metal in the form of a carbide instead of precipitating out in the form of graphite, which results in gray iron or spheroidal/nodular iron. Materials which promote carbide formation and deter graphite formation, such as tellurium, bismuth or antimony have been heretofore coated on mold surfaces fixed in the filling area, or have been placed in the mold in the form of an insert, for example, as described in Falk U.S. Pat. No. 5,524,497 issued Jun. 11, 1996 or U.S. Pat. No. 4,570,496 issued Feb. 18, 1986. U.S. Pat. No. 4,059,996 shows a technique using a "blob" of such material in a cup type mold cavity. Another device for providing an additive such as tellurium to a mold for obtaining samples for spectrographic analysis is described in U.S. Pat. No. 5,057,149 wherein the additive is placed between two flat metal layers.
A need has, however, continued to exist for additional improved techniques for consistently obtaining uniform, homogeneous dense, fine grained metallurgical white iron samples, even if the metal contains high carbon contents or has a high carbon equivalent. Carbon equivalent is defined in U.S. Pat. No. 3,546,921, issued Dec. 15, 1970.